Tuberculosis (TB) in the industrial/developed world is no longer the scourge of humans that it once was. However, it still is in the bodies of over one-third of the world's population.

According to an October 2006 report by the World Health Organisation (WHO), a new case of TB occurs somewhere in the world every second of every day. In 2004, there were 14.6 million people with active TB.

TB stands for Tubercle Bacillus. TB is caused by a bacterium, Mycobacterium tuberculosis. Fortunately, not everyone who is infected develops the disease. Fortunately too, not everyone dies who develops the disease - even if they do not receive treatment.

Approximately one in 10 of those infected with TB develops the disease. This is called active TB. In cases of active TB, if the individual receives no treatment, the person has about a 50 per cent chance of dying. One of the most worrying problems in the international public health field today is that TB cruelly attacks people with a compromised immune system. In Sub-Saharan Africa, where the AIDS epidemic does precisely this, TB often attacks weakened individuals with fatal consequences. TB also wreaks havoc with those with substance abuse problems.

Does tuberculosis only affect the lungs?

Contrary to popular belief, TB is not a disease that only affects the lungs. TB that affects the lungs is called pulmonary TB. Seventy per cent per cent of TB cases are pulmonary TB. But TB can also affect the brain, the lymphatic system, the circulatory system, genitourinary system, bones, and joints.

Pulmonary TB is the most common type of TB in the UK, Europe, Canada, the US, Australia, and the rest of the industrial/developed world. In nations that can afford modern systems of health care, pulmonary TB comprises about 90 per cent of the active human cases.

However, the infectious bacteria can establish themselves in every human tissue or organ. For example, TB can infect the central nervous system. This discovery was made 40 years ago by two doctors by the name of Dastur and Udani. They called it tuberculosis encephalopathy.

Dr G A Lammie and three colleagues from the Department of Pathology at Cardiff University in Wales write in the ACTA Neuropathologica (14 December 2006) that tuberculosis encephalopathy "is now established in the tuberculosis literature". Because TB is usually acquired by the inhalation or ingestion of infected material, the lungs and intestines are the most likely locations of the illness.

But TB is a group of infectious disease and only because of modern drugs and adequate public health care facilities are the other types of TB so uncommon in industrial/developed countries.

What is the difference between tuberculosis and consumption?

TB has been known by many names. "Consumption" is one of these. In ancient Greece TB was known as phthisis, meaning consumption, and sometimes even phthisis pulmonalis. Among other names, TB has also been called wasting disease, white plague, and king's evil. The last name also implied that it was only the touch of a king that could cure TB. Now we have fewer kings and more drugs.

Stephen Juan, Ph.D. is an anthropologist at the University of Sydney. Email your Odd Body questions to s.juan@edfac.usyd.edu.au